Add "hit"/"miss" statistics for queries

[cudeso]

Track the queries that returned a hit or did not return a hit.
Track per hash and have a "namespace".

• handy when importing sets from other sources
• run over all files in a disk, track which files have been seen, which one haven't been seen
• per "dfir"-session
• get statistics afterwards
• option to query and reset statistics, per session
• store on db side

[adulau]

Thanks a lot for the ideas.

• For tracking queries, I'll add table of hashes with hits and no hits. It will also add a pub-sub channel for it.

• For the session, that's a clever idea. Something like Ubuntu Bionic default session and we could even save the set and make it available if other parties are interested.

[adulau]

• Pub-sub functionality for hit-missed added in 31ac93e
• Add a hit/miss zrank option to add statistics in 72b462b
• Support statistics for bulk search too
• Add a new API endpoints to paginate over the statistics
• Add a new option for session creation with TTL